Welding Tips and Tricks

Really basic here I think but wouldn't mind this explained.

I ran across this in the reference side of a blueprint the other day.

** Weld size to be 1x the minimum material thickness **

So just wondering if that means what i think it means.. If the material is 1/2" that then states that the fillet weld is supposed to be 1/2??

Thanks in advanced!!

If both sides are 1/2inch then yes. But if your welding 1/4 to 1/2 then 1/4inch would be the requirement.

"If both sides are 1/2inch then yes. But if your welding 1/4 to 1/2 then 1/4inch would be the requirement."

josh
would the inverse (welding a piece of 1/2" to a larger piece of `1/4") be the proper assumption?
craig

According to the note he quoted. That is a common note. Every inspector I’ve dealt with has interpreted it that way. If it’s a fillet weld then what piece is being welded on to the other is irrelevant, as long as it matches the requirements of the thinner metal. Think Jody talked about it some in one of his recent videos. You can buy a gauge set that checks the leg length and the thickness of the throat.

@ TheBeardedWelder - what welding code/specification is the basis for your blueprint?

Background context for you regarding fillet weld sizing. Most commonly in blueprints, the 'size of the weld' is the leg length, not the throat dimension.

From a design perspective, all welds are assumed to fail in shear. The Minimum Size of Fillet Weld tables below are from AWS D1.1 (2000), AWS D1.1 (2010), and AWS D14.4 (2012). D1.1 is Structural Welding Code - Steel; D14.4 is Specification for the Design of Welded Joints in Machinery and Equipment.


AWS D1.1 (2000) :: for base metal thickness of 1/2", a weld size of 3/16" is the minimum.

AWS D1.1 (2010) :: for base metal thickness of 1/2", a weld size of 3/16" is the minimum.

AWS D14.4 (2012) :: for base metal thickness of 1/2", a weld size of 3/16" is the minimum.

<< Regardless of the above discussed minimums, your blueprint ultimately controls your weld size. 1/2" in your case. >>

Having discussed the minimum sizing of fillet welds, an over-allowance (reinforcement) in the fillet weld is permissible. The designer drives this over-allowance, and the welder controls during the process. Professionally, do not like the term "reinforcement" in this application as the added metal does nothing to add strength to a given weld. Perhaps the AWS controlling committees will excise the word and just use "over-allowance".

** The above tables are not idealized for Fatigue related applications, where stress range and stress categories need to be determined/applied. If you are interested in learning more about Fatigue applications for welding, Then encourage you to explore AISC 360, Appendix 3. The ref is online for free.**


"Fatigue is the result of repeated plastic deformation" (Omer W. Blodgett)

"Fatigue damage of components subjected to normally elastic stress fluctuations occurs at regions of stress/strain risers were localized stress exceeds the yield stress of the material. After a certain number of load fluctuations, the accumulated damage causes the initiation and subsequent propagation of a crack, or cracks, in the plastically damaged regions." (Barsom and Rolfe)

does "over alliance " refer to the leg or the throat or both?
craig

motox wrote:does "over alliance " refer to the leg or the throat or both?
craig

The Reinforcement, in the Fillet joint diagram, is the volume of material subtended by the dotted line (Toe to Toe) to the apex of the Face. None of that added filler material does anything to the strength of the weld. Similarly in the Groove joint diagram, the Reinforcement is the filler volume from the dotted line (Toe to Toe) to the apex of the Face. Again, no gain from fusing this added material to the weld Face.

AWS D1.1 specifies a maximum of 1/8in of "Reinforcement" for Groove welds.

Ok.. I think i got it. That chart shows a range of thicknesses and the min weld is within that range... Sounds almost tooo easy..

TheBeardedWelder wrote:Ok.. I think i got it. That chart shows a range of thicknesses and the min weld is within that range... Sounds almost tooo easy..